Ch 5 Review

1. Mouse Mischief Ch 5 Review

2. When a machine is used to do work, the force applied by the machine is called the effort force.

3. Under certain conditions, it is possible to get more work out of a machine than you put into it.

4. Some machines don't multiply the force that is applied to them.

5. Examples of all three classes of levers are found in the human body.

6. In order for work to be done on a object, the object must move.

7. Actual mechanical advantage is determined with the equation MA = Fr/Fe.

8. Power is work done over a distance

9. The longer arm of a lever with a mechanical advantage greater than 1 is the effort arm.

10. Friction changes the useful work of a machine into mechanical energy.

11. Reducing friction increases the ideal mechanical advantage of a machine.

12. If a weight lifter is holding barbells above his head, what does he have to do to perform work? stand still step forward move barbells sideways lower barbells

13. The fixed pulley shown in Figure 5-1 does which one of the following? doubles the force required to lift the block decrease the force required to lift the block makes the block easier to lift by changing the direction of the force needed to lift it decreases the force required and changes the direction of the force required

14. A slanted surface used to raise an object is a(n) ____. efficiency board inclined plane effort ramp screw

15. A device that does work with only one movement and changes the size or direction of a force is a(n) ____. compound machine effort machine screw simple machine

16. A bar that is free to pivot about a fixed point is a ____. fulcrum lever ramp screw

17. The rate at which work is done is called ____. efficiency effort time force power

18. The amount by which a machine multiplies an effort force is called the ____. efficiency factor fulcrum mechanical advantage resistance force

19. An inclined plane with one or two sloping sides forms a machine called a ____. pulley lever ramp wedge

20. An inclined plane wrapped around a cylindrical post is a ____. block and tackle lever ramp screw

21. A machine that changes only the direction of a force has a mechanical advantage of ____. 100 10 5 1

22. A winding mountain road is an example of a(n) ____. block and tackle lever inclined plane wheel and axle

23. When two or more simple machines work together, they are called a(n)____. compound machine effort machine screw simple machine

24. The unit of power is the ____. joule watt m/s second

25. A lever with a mechanical advantage greater than 1 is used to ____. change direction increase distance increase force increase force and change direction

26. Three of the following simple machines are basically the same. The one that does NOT belong with the group is the ____. lever pulley wedge wheel and axle

27. An arrangement of pulleys designed to reduce the effort force is called a ____. block and tackle fixed pulley movable pulley simple pulley

28. Two simple machines that are part of a bicycle are a(n)____. gear and a wheel and axle inclined plane and a lever inclined plane and a wedge screw and an inclined plane